615 Background: Recently, radioactive tracer, a vital dye, or a combination of both has been applied intraoperatively to detect sentinel lymph nodes (SLN) for patients with early breast cancers. We present a novel method of SLN identification using near-infrared fluorescence imaging that provides with high detection and low false-negative rates. Materials and Methods: This study enrolled 52 patients with a tumor less than 3 cm in diameter. Their mean age was 54.7 years. Preoperative TNM stage was I in 35 cases, IIa in 12, and IIb in 5, respectively. Initially the combination dye of indocyanine green and indigocarmine was injected subdermally in the areola. Fluorescence imaging (photodynamic eye: Hamamatsu Photonics Co.) was obtained using a charge coupled device camera with a cut filter as the detector, and light emitting diodes at 760 nm as the light source. Subcutaneous lymphatic channels draining from the areola to the axilla or other directions were visible by fluorescence imagings immediately. After incising the axillary skin 1 cm cranial side from the disappeared point of fluorescence image, SLN was then dissected under the guidance of fluorescence. Results: In all but one patient, lymphatic channels and SLN were successfully visualized (identification rate: 98.1%). SLN was observed before skin incision in two patients. The number of fluorescence SLN ranged from 0 to 11 (mean: 4.7) and blue dyed SLN ranged from o to 6 (mean: 2.0). SLN was not identified in one patient in the former and 7 patients in the latter. Twelve patients had lymph node metastases pathologically. All of them were recognized by fluorescence imaging, however, three patients with metastatic LN were not identified by a vital dye. Conclusions: This method is feasible and safe to detect SLN intraoperatively with less invasive, real-time observation and no requirement of training. We are convinced that this method will provide with high detection and low false-negative rates in SLN navigation surgery. No significant financial relationships to disclose.
Direct visualization of changes of lymphatic function and drainage pathways in lymph node metastasis of B16F10 melanoma using near-infrared fluorescence imaging
